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MVVM模式是Model-View-ViewModel模式的简称，也就是由模型（Model）、视图（View）、视图模型（ViewModel），其目的是为了实现将业务和界面分开，降低耦合度。
总体结构：
View层代码：
<Label Content="购买数：" Style="{StaticResource LabStyle}" Grid.Row="3" Grid.Column="0" /> <TextBox Grid.Row="3" Grid.Column="1" Style="{StaticResource TextBoxStyle}" Text="{Binding BuyTextBox,UpdateSourceTrigger=PropertyChanged}"> </TextBox> <ComboBox Grid.Row="0" Grid.Column="1" Style="{StaticResource ComboxStyle}"> <ComboBoxItem Content="西瓜" /> </ComboBox> <ComboBox Grid.Row="1" Grid.Column="1" Style="{StaticResource ComboxStyle}" ItemsSource="{Binding Prices}" SelectedItem="{Binding SelectPrice, UpdateSourceTrigger=PropertyChanged}"> </ComboBox>
ViewModel层代码
/// <summary> /// 设置购买量属性 /// </summary> public int BuyTextBox { get { return m_buyNum; } set { m_buyNum = value; //计算金额 m_money = m_selectPrice*m_buyNum; if (m_buyNum > m_surplus) { MessageBox.Show("购买数量大于剩余数量，请重新输入购买数量！"); m_buyNum = 0; m_money = 0; } OnPropertyChange<CalculateFruitVm>(vm => vm.BuyTextBox); } }
/// <summary> /// 设置价格属性 /// </summary> public ObservableCollection<int> Prices { get { return m_prices; } set { m_prices = value; OnPropertyChange<CalculateFruitVm>(vm => vm.Prices); } }
/// <summary> /// 设置选择价格属性 /// </summary> public int SelectPrice { get { return m_selectPrice; } set { m_selectPrice = value; m_money = m_selectPrice*m_buyNum; OnPropertyChange<CalculateFruitVm>(vm => vm.SelectPrice); } }
/// <summary> /// 构造函数CalculateFruitVm /// </summary> public CalculateFruitVm() { m_prices.Add(4); m_selectPrice = 4; m_prices.Add(5); }
注意：这里是在构造函数CalculateFruitVm中设置价格并选择价格，因价格是combox控件，除了需要设置价格属性外，还需要设置价格选择属性。
Button按钮
View层代码
<Button Content="返回" Grid.Column="2" Style="{StaticResource ButtonStyle}" HorizontalAlignment="Left" Command="{Binding CancleCommand}"></Button>
ViewModel层代码
/// <summary> /// CancleCommand命令 /// </summary> public ICommand CancleCommand { get { return m_cancelCommand; } }
/// <summary> /// 构造函数CalculateFruitVm /// </summary> public CalculateFruitVm() { m_cancelCommand = ICommandFactory.CreateCommand(CancelCmdExecute, CanCancelCmdExecute); }
/// <summary> /// 声明CancelEvent事件 /// </summary> public event EventHandler<EventArgs> CancelEvent; /// <summary> /// CanCancelCmdExecute事件 /// </summary> /// <param name="arg"></param> /// <returns></returns> private bool CanCancelCmdExecute(object arg) { return true; }
/// <summary> /// CancelCmdExecute事件 /// </summary> /// <param name="obj"></param> private void CancelCmdExecute(object obj) { if (CancelEvent != null) { CancelEvent(this, EventArgs.Empty); } }
.xaml.cs代码
public CalculateFruit() { InitializeComponent(); CalculateFruitVm calculateFruitVm = new CalculateFruitVm(); DataContext = calculateFruitVm; calculateFruitVm.CancelEvent += calculateFruitVm_CancelEvent; }
/// <summary> /// 点击返回按钮，返回主界面 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void calculateFruitVm_CancelEvent(object sender, EventArgs e) { MainWindow mainWindow = new MainWindow(); mainWindow.Show(); this.Hide(); }
Button按钮需要在View层用command绑定事件，ViewModel中创建命令、构造函数、声明事件，最后在.xaml.cs中加载ViewModel，并实现界面跳转、关闭等操作。
MVVM 中更好的实现了面向对象中的继承和封装，所有的命令都继承自ICommand接口，将所有的命令用ViewModel层去实现。
当界面之间需要互相传值时，需要在VM中传递界面需要的值，实例化需要传到哪个界面的VM，示例如下：
隐藏事件
private void HideCmdExecute(object obj) { if (m_buyNum > 0 && m_selectPrice > 0) { if (HideEvent != null) { //计算剩余量 m_surplus -= m_buyNum; //计算售卖总量 CalculateNum += m_buyNum; //计算售卖总金额 CalculateMoney += m_money; //new出ResultCalculateVm并赋值 ResultCalculateVm resultCalculateVm = new ResultCalculateVm(); resultCalculateVm.SalesNumberTextBox = CalculateNum; resultCalculateVm.TotalMoney = CalculateMoney; resultCalculateVm.TotalSurplus = m_surplus; HideEvent(this, new FruitEventArgs {ResultCalculateVm = resultCalculateVm}); } } }
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原文地址：http://www.cnblogs.com/xiangyueqiaomai/p/5744560.html
